Microplastics are small plastic particles derived from the degradation of plastics, which have been detected in both humans and wildlife - many marine species are affected – plus the drinking water and foods we consume. The dramatic findings of microplastics in the human brain were recently published in a groundbreaking study in Nature.
"The dramatic increase in brain microplastic concentrations over eight years (2016 to 2024) is particularly alarming," explains commentary lead author Dr. Nicholas Fabiano, a Faculty of Medicine resident and lifestyle psychiatry researcher. "This rise mirrors the exponential increase we're seeing in environmental microplastic levels."
Limiting microplastic intake
In a commentary published in Brain Medicine, Dr. Fabiano and his co-authors Dr. Brandon Luu (University of Toronto) and Dr. David Puder emphasize the urgent need for large-scale human studies to determine dose-response relationships between microplastic exposure and chronic health outcomes and the establishment of clear exposure limits to help assess the long-term health consequences of microplastic accumulation.
Of particular concern are particles smaller than 200 nanometers, predominantly composed of polyethylene, which show notable deposition in cerebrovascular walls and immune cells. This size allows them to potentially cross the blood-brain barrier, raising questions about their role in neurological conditions. There is scarce evidence microplastics can be removed naturally from the body, with natural sweat offering limited potential.
“It is important for the public to be aware of the increasing amounts of microplastics in the environment and uptake into our bodies. We should also understand the methods available to help reduce microplastic intake while research continues seeking methods to their removal from our bodies, which continues to be scarce in evidence,” says Fabiano, who Genomic Press named a rising star for his innovative work in lifestyle psychiatry.
Solutions to a growing public health worry
A significant amount of microplastics (90,000 to 4,000 per year) can be cut by simply drinking tap water over plastic bottled varieties. Plastic tea bags release millions of particles per brew, while food stored in plastic containers and then microwaved in them can also release substantial amounts. Reducing the consumption of ultra processed and canned food, alcohol and seafood, and installing air filters in your home can also prove beneficial.
The potential mental health implications cannot be discounted, as ultra-processed foods, which are known to have high levels of microplastics, have been associated with worsening of mental health, particularly depression and anxiety. “More research is needed to delineate this relationship”, says Fabiano.
“Beyond education at the individual level, there is responsibility from a government policy perspective to reduce microplastic exposure broadly, thereby minimizing potential long-term health consequences as the evidence base continues to grow,” says Fabiano, whose research focuses on bridging the benefits of physical and mental health for the body.
“Logically, having a spoon’s worth of plastics in your brain can’t be a good thing.”
‘Human microplastic removal: what does the evidence tell us?’ was published in Brain Medicine on March 4, 2025.
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